The present technology relates to non-volatile memory.
One type of non-volatile memory cell uses a charge trapping region to store information. As one example, the memory cell is a transistor that has a stack of films adjacent to the memory cell channel. Moving in a direction away from the channel, there is a tunnel dielectric, a charge trapping region, a blocking oxide, and a control gate. The memory cell is programmed by injecting electrons from the memory cell channel into the charge trapping region, where they are trapped and stored. This stored charge then changes the threshold voltage of the cell in a manner that is detectable. The cell may be erased by injecting holes from the channel into the charge trapping region where they recombine with electrons, and thereby “cancel” or reduce the stored charge. Cells may be also erased by extracting electrons from the charge trapping region, e.g., by applying an electric field making electrons tunnel from the charge trapping region to the channel. Cells may be erased by a combination of the two mechanisms above.